Paraneoplastic Syndromes (Lecture 3)

Slide 1 · Paraneoplastic Syndromes

Immune-mediated disorders of the nervous system

CNS • peripheral nerves • neuromuscular junction

Dr Abu Suraih Sakhri

MBBS, MD (Pathology)

www.abusuraihsakhri.com

Slide 2 · Learning objectives

Explain why a tumor outside the nervous system can cause neurologic dysfunction.

Localize the major paraneoplastic syndromes to their nervous-system targets.

Connect each syndrome to its morphology, associated antibodies and tumor context.

Distinguish structural neuronal injury from antibody-associated functional impairment.

Apply these relationships to clinicopathologic vignettes.

Slide 3 · The neurologic scope of this lecture

Central nervous system

Peripheral nervous system

Neuromuscular junction

Subacute cerebellar degeneration

Subacute sensory neuropathy

Lambert–Eaton myasthenic syndrome

Limbic ± brainstem encephalitis

Dorsal root ganglion injury

Presynaptic calcium-channel dysfunction

Opsoclonus ± myoclonus

May accompany limbic disease

May occur without cancer

Slide 4 · Paraneoplastic is not direct tumor invasion

A peripheral neoplasm may cause neurologic disease without growing into nervous tissue.

The neurologic manifestations are not adequately explained by a CNS metastatic mass.

An immune response directed toward shared tumor–neural antigens is a central mechanism.

A neurologic presentation may occur before the primary malignancy is recognized.

Slide 5 · Paraneoplastic disease versus CNS metastasis

Direct metastatic effect

Neoplastic cells reach the CNS.

Local mass, edema or meningeal tumor causes injury.

Morphology can reveal malignant cells.

Paraneoplastic immune effect

Peripheral tumor induces anti-neural immunity.

CNS or PNS tissue may be injured without local tumor.

Inflammation and selective neuronal loss may dominate.

Slide 6 · Neurologic symptoms may reveal occult cancer

Neural syndrome

First clinical manifestation

Tumor evaluation

Search prompted by phenotype

Tumor identified

Recognition may follow neurologic illness

Temporal precedence makes syndrome recognition clinically important.

Slide 7 · Shared antigen: Proposed immune sequence

Peripheral tumor expresses antigen

Host mounts an immune response

Immune response cross-reacts with neural antigen

Neural dysfunction or cell injury

Immune recognition is directed at the tumor but can harm the nervous system.

This as the shared mechanism across multiple syndromes.

SCHEMATIC — CAUSAL RELATIONSHIP

Slide 8 · A tumor antigen can resemble a neuronal target

Antigen in tumor tissue

Immune cross-reactivity

Shared neural antigen

CNS/PNS injury

This is a mechanistic schematic, not proof that every detected antibody is pathogenic.

Chapter 7 describes cellular as well as antibody-associated responses.

SCHEMATIC — CAUSAL RELATIONSHIP

Slide 9 · Antibody detection is not identical to causation

Circulating antibody

May identify a characteristic immune response.

Can provide an association with a tumor context.

Its presence alone does not prove direct injury.

Cell-mediated response

Chapter 7 describes T-cell responses to neural antigens.

Chapter 27 describes CD8+ cytotoxic injury in sensory neuronopathy.

The dominant effector mechanism can differ by syndrome.

Slide 10 · Three injury mechanisms in one clinical field

Site of injury

Representative lesion

Pathophysiologic effect

Cerebellar cortex

Purkinje-cell destruction and gliosis

Loss of cerebellar circuit function

Temporal limbic tissue

Perivascular inflammation, neuronal loss

Encephalitic cognitive syndrome

Presynaptic NMJ

Calcium-channel–directed antibodies

Impaired acetylcholine release

Slide 11 · Map syndromes to neural compartments

Cerebellum

Purkinje-cell loss

Limbic system

Temporal inflammation

Brainstem / eye movement

Opsoclonus ± myoclonus

Dorsal root ganglion

Sensory neuron loss

Neuromuscular junction

Presynaptic transmission defect

Slide 12 · Tumor associations are clues, not identities

Neurologic syndrome / marker

Associated tumor context

Qualification

PCA-1–associated cerebellar degeneration

Ovarian, uterine or breast carcinoma

Predominant association in described subgroup

Neuronal nuclear antibody / encephalitis

Small cell lung carcinoma

Most often associated in described subgroup

NMDA receptor encephalitis

Ovarian teratoma

Can also be non-paraneoplastic

Childhood opsoclonus

Neuroblastoma

Characteristic childhood association

Slide 13 · Distinguish localization from tumor identification

The neurologic phenotype identifies which neural compartment is impaired.

Pathology and antibody findings help define the immune syndrome.

An associated cancer type helps direct suspicion, but is not a diagnosis by itself.

A tumor may still be occult when neurologic pathology becomes apparent.

Slide 14 · Purkinje cells: The principal lesion target

SCHEMATIC CEREBELLAR CORTEX

Molecular layer

Purkinje layer

Granule layer

The cerebellar cortex is the site of selective Purkinje-cell injury.

Dendritic arbor, cell body and outgoing axon are shown schematically.

Slide 15 · Subacute cerebellar degeneration: Causal chain

Paraneoplastic immune response

Purkinje-cell injury and destruction

Gliosis and chronic inflammation

Loss of cerebellar function

Purkinje-cell destruction as the characteristic tissue lesion.

SCHEMATIC — CAUSAL RELATIONSHIP

Slide 16 · The pathology centers on Purkinje-cell loss

SCHEMATIC CEREBELLAR CORTEX

Molecular layer

Purkinje layer

Granule layer

Missing Purkinje cell

Loss of Purkinje neurons is a defining morphological feature.

Schematic comparison: Preserved neurons versus neuronal depletion.

Slide 17 · Gliosis accompanies neuronal destruction

Reactive gliosis is part of the described cerebellar lesion.

Gliosis documents a tissue response to injury; It does not replace lost Purkinje neurons.

The pattern supports a destructive rather than purely transient functional disorder.

Interpret gliosis together with cellular loss and inflammatory findings.

Slide 18 · Chronic inflammatory infiltrates complete the pattern

Chronic inflammatory cells occur within affected cerebellar tissue.

The infiltrate accompanies loss of Purkinje cells and gliosis.

The combination is consistent with an immune-mediated destructive process.

None of these features, in isolation, proves the identity of an underlying cancer.

Slide 19 · Morphology–function correlation: Cerebellum

Purkinje-cell destruction

Impaired cortical output

Gliosis

Tissue response to neuronal injury

Cerebellar dysfunction

Subacute disturbance of coordination

Clinical correlation: Impaired coordination is expected from cerebellar circuit dysfunction.

Slide 20 · PCA-1 identifies one immune-associated subgroup

PCA-1 means Purkinje cell cytoplasmic antibody type 1.

It recognizes cerebellar Purkinje cells.

PCA-1 in a subgroup of affected patients; Not in all cases.

Antibody recognition and neuronal destruction are distinct observations.

Slide 21 · PCA-1: Characteristic associated carcinomas

Ovarian carcinoma

Uterine carcinoma

Breast carcinoma

PCA-1 is reported in this tumor context.

Also in the reported tumor spectrum.

Also in the reported tumor spectrum.

Association supports tumor evaluation.

It is not tumor-specific proof.

No prevalence estimate is asserted here.

Slide 22 · Cerebellar degeneration versus metastatic mass

Immune cerebellar injury

Selective Purkinje-cell loss

Gliosis and chronic inflammatory cells

Cancer may be outside the CNS

CNS metastasis

A neoplastic deposit within brain tissue

Localized mass or meningeal distribution

Tumor cells establish direct disease

Slide 23 · Vignette: Progressive cerebellar dysfunction

TEACHING VIGNETTE

An adult develops a subacute loss of coordination.

Pathology shows marked loss of cerebellar Purkinje cells with gliosis.

Serum demonstrates PCA-1 reactivity.

Which underlying tumor types would this pattern particularly raise concern for?

Slide 24 · Cerebellar vignette: Reason from the lesion

Evidence

Interpretation

Purkinje-cell loss + gliosis

Supports subacute cerebellar degeneration

PCA-1 antibody

Identifies the described antibody-associated subgroup

Associated neoplasms

Ovarian, uterine and breast carcinomas are listed

Absent CNS mass in vignette

Does not exclude an occult peripheral tumor

Slide 25 · Limbic involvement favors medial temporal structures

SCHEMATIC LOCALIZATION

Anterior / medial temporal region

The inflammatory and neuronal injury is most conspicuous in anterior and medial temporal regions.

Schematic outline emphasizes relative localization, not histologic evidence.

Slide 26 · Limbic encephalitis may cause subacute dementia

Robbins characterizes the syndrome by subacute dementia.

The tissue changes involve anterior and medial portions of temporal lobes.

The tempo and anatomic localization support an encephalitic process.

A neurological presentation may precede discovery of a peripheral tumor.

Slide 27 · Limbic injury connects anatomy to cognition

Immune attack on limbic tissue

Temporal-lobe inflammatory lesions

Neuronal loss and gliosis

Subacute cognitive impairment

The causal interpretation is consistent with the described morphology and phenotype.

SCHEMATIC — CAUSAL RELATIONSHIP

Slide 28 · Perivascular inflammatory cuffs

ORIGINAL MORPHOLOGY SCHEMATIC

Vessel

Inflammatory cells cluster around small vessels.

Schematic inflammatory pattern — not a microscopic specimen.

Slide 29 · Microglial nodules

ORIGINAL MORPHOLOGY SCHEMATIC

Activated microglial cells aggregate in nodular foci.

Schematic of a reported histologic pattern — not real H&E.

Slide 30 · Neuronal loss and gliosis

ORIGINAL MORPHOLOGY SCHEMATIC

Neuron lost

Some neurons are lost; Surrounding tissue shows gliosis.

Simplified injury pattern; No actual biopsy image represented.

Slide 31 · Four characteristic microscopic findings

Inflammatory features

Parenchymal response

Perivascular lymphocytic cuffs

Microglial nodules

Inflammation within affected temporal regions

Loss of some neurons

Can resemble viral encephalitis

Reactive gliosis

Slide 32 · The histology can resemble viral encephalitis

Perivascular inflammation and microglial nodules are not uniquely paraneoplastic.

The resemblance to viral encephalitis.

Clinicopathologic interpretation must incorporate tempo, tumor context and antibodies.

Do not infer a neoplastic cause from inflammatory histology alone.

Slide 33 · Brainstem involvement may accompany limbic injury

SCHEMATIC LOCALIZATION

Brainstem

Comparable inflammation can involve the brainstem.

Brainstem disease may be isolated or occur together with limbic encephalitis.

Slide 34 · Neuronal nuclear antibodies: One subtype

Some patients have circulating antibodies that recognize neuronal nuclei.

Antibody recognition occurs in both CNS and peripheral nervous-system neurons.

The reported tumor association is most often small cell carcinoma of lung.

The antibody result must be interpreted with the neurologic syndrome.

Slide 35 · Small cell carcinoma: Neural immune association

Small cell lung carcinoma

Anti-neuronal immune response

CNS/PNS neuronal antigen recognition

Limbic and sometimes peripheral disease

The malignancy is a clinical association, not a requirement in every encephalitis case.

SCHEMATIC — CAUSAL RELATIONSHIP

Slide 36 · NMDA receptor antibodies: A different target

Another reported group has antibodies recognizing the NMDA receptor.

The antibodies cross-react with hippocampal neurons.

This differs in target class from antibodies recognizing neuronal nuclei.

The corresponding syndrome can arise in neoplastic or non-neoplastic settings.

Slide 37 · NMDA receptor and ovarian teratoma

Neural antigen

NMDA receptor on neural cell membrane

Anatomic correlation

Hippocampal neuronal recognition

Tumor context

Originally identified with ovarian teratomas

This is an association; It is not a universal cause of anti-NMDA receptor encephalitis.

Slide 38 · Anti-NMDA receptor encephalitis is not always cancer-related

The same clinical syndrome occurs in a proportion of sporadic encephalitis cases.

An anti-neuronal syndrome is not, by itself, evidence of cancer.

The ovarian teratoma association remains an important tumor-related context.

Separate antigen-defined phenotype from paraneoplastic status.

Slide 39 · VGKC-complex antibodies terminology

A subgroup with circulating VGKC-complex antibodies.

The textbook relates this antibody group to the limbic encephalitis spectrum.

An associated peripheral neuropathy is also described.

“VGKC-complex” is the term in the supplied text; No antigen-specific modern reassignment is inferred.

Slide 40 · A CNS syndrome may coexist with peripheral neuropathy

Medial temporal lobe

Encephalitic cognitive dysfunction

Neuronal nuclei / related antigen

Immune recognition may span CNS and PNS

Peripheral nerves

Neuropathy may accompany limbic disease

Slide 41 · Antibody-defined illustrations in the source

Reported antibody group

Neural recognition / context

Major qualification

Neuronal nuclear

CNS and PNS neuronal nuclei; Small cell lung cancer

Reported in some patients

NMDA receptor

Hippocampal neurons; Ovarian teratoma

Also non-neoplastic encephalitis

VGKC-complex

Limbic encephalitis; Sometimes neuropathy

Textbook umbrella terminology

Slide 42 · Vignette: Temporal inflammatory syndrome

TEACHING VIGNETTE

An adult presents with subacute cognitive deterioration.

Temporal-lobe pathology demonstrates perivascular cuffs and microglial nodules.

A circulating antineuronal nuclear antibody is detected.

Which cancer association is emphasized, and what histologic mimic matters?

Slide 43 · Limbic vignette: Two distinct inferences

Finding

Reasoned inference

Subacute dementia + temporal inflammation

Consistent with limbic encephalitis

Neuronal nuclear antibody

Raises a characteristic paraneoplastic antibody association

Associated malignancy

Small cell lung carcinoma is emphasized

Cuffs and microglial nodules

Viral encephalitis is a morphologic mimic

Slide 44 · Opsoclonus is an eye movement disorder

SCHEMATIC EYE MOVEMENTS

Opsoclonus is the eye movement abnormality highlighted in this neurologic paraneoplastic group.

Uncontrolled eye movements may appear alone or as part of wider dysfunction.

Slide 45 · Eye movement abnormalities may signal broader neural disease

Opsoclonus as the most common ocular movement example.

It may occur without other neurologic manifestations.

It may accompany cerebellar or brainstem dysfunction.

Localize the complete phenotype, rather than stopping at an ocular sign.

Slide 46 · Opsoclonus and myoclonus can occur together

Eye movements

Opsoclonus

Motor accompaniment

Myoclonus

Possible additional sites

Cerebellum and brainstem

This combined phenotype is emphasized particularly in children.

Slide 47 · Childhood opsoclonus: Neuroblastoma association

In children, opsoclonus is most often associated with neuroblastoma.

Myoclonus frequently accompanies the eye movement disorder.

Recognition of the characteristic combination can motivate tumor investigation.

The term “associated” must not be misread as “present in all cases.”

Slide 48 · Vignette: Abnormal eye movements in a child

TEACHING VIGNETTE

A child develops conspicuous involuntary eye movements.

Brief, sudden myoclonic movements accompany the ocular abnormality.

There is no described intracranial mass.

Identify the neurologic syndrome and its characteristic childhood tumor association.

Slide 49 · Opsoclonus vignette: Anatomical reasoning

Observed problem

Associated interpretation

Characteristic multidirectional eye movement disorder

Opsoclonus

Accompanying involuntary jerks

Myoclonus

Typical childhood tumor association

Neuroblastoma

No demonstrated CNS mass

An immune paraneoplastic process remains possible

Slide 50 · Cancer-related neuropathy has multiple mechanisms

Direct or therapy-related

Paraneoplastic immune-mediated

Tumor compression or nerve infiltration

Neuron-directed autoimmune injury

Antineoplastic drug toxicity

Neuropathy may precede cancer diagnosis

Can cause localized or diffuse damage

Sensory neuronopathy is a described pattern

Slide 51 · Subacute sensory neuropathy: Primary target

SCHEMATIC DORSAL ROOT GANGLION

Dorsal root ganglion sensory neurons are the affected cell population.

The morphologic substrate is neuronal loss within ganglia.

Slide 52 · Dorsal root ganglion cell loss with inflammation

SCHEMATIC DORSAL ROOT GANGLION

The ganglia show loss of sensory neurons and lymphocytic inflammation.

Schematic represents site and cell types, not tissue imaging.

Slide 53 · Sensory neuronopathy can accompany limbic disease

Subacute sensory neuropathy may occur on its own.

It may also accompany limbic encephalitis.

Both presentations fit a neural immune response that is not restricted to the brain.

Localization to dorsal root ganglia explains why neuronal loss is central to morphology.

Slide 54 · Paraneoplastic sensory symptoms can be asymmetric

Chapter 27 describes distal onset with an asymmetric, multifocal sensory pattern.

Sensory neuronopathy is an important cancer-related immune neuropathy.

The pattern differs from a single nerve compressed by a localized tumor.

Clinical distribution complements ganglion pathology in localization.

Slide 55 · ANNA-1 (anti-Hu) and sensory neuron injury

Chapter 27 describes anti-Hu antibodies as antineuronal nuclear antibody type 1.

These antibodies may recognize proteins in tumor cells and normal neurons.

The described ganglion injury appears to be mediated by CD8+ cytotoxic T cells.

This illustrates the difference between an antibody marker and a cellular effector.

Slide 56 · Sensory neuronopathy and small cell lung cancer

Chapter 27 associates paraneoplastic sensory neuronopathy most often with small cell lung cancer.

The neurologic illness may precede cancer identification.

Neural antibodies support a specific immune context rather than demonstrating a tumor deposit.

The clinicopathologic pattern helps distinguish ganglionitis from direct neuropathy.

Slide 57 · Ganglionitis is distinct from axonal compression

Sensory ganglionitis

Target: Ganglion neuronal cell body

Neuronal loss and lymphocytic inflammation

Can be multifocal and paraneoplastic

Direct neoplastic neuropathy

Target: Infiltrated or compressed nerve

Neoplastic mass or infiltrating cells

Distribution follows sites of direct injury

Slide 58 · Normal neuromuscular transmission

EDITABLE PHYSIOLOGY SCHEMATIC

Presynaptic motor nerve terminal

Muscle end plate (postsynaptic)

Ca²⁺ entry

A nerve impulse triggers presynaptic calcium entry and acetylcholine release.

Acetylcholine acts on postsynaptic muscle receptors.

Slide 59 · LEMS attacks presynaptic calcium channels

EDITABLE PHYSIOLOGY SCHEMATIC

Presynaptic motor nerve terminal

Muscle end plate (postsynaptic)

Antibody inhibition

Antibodies inhibit voltage-gated calcium channels on the nerve terminal.

Calcium-dependent acetylcholine release is reduced.

Slide 60 · From channel inhibition to muscle weakness

Antibodies bind presynaptic Ca²⁺ channels

Reduced calcium-dependent ACh release

Less effective neuromuscular transmission

Extremity weakness

This is a presynaptic transmission disorder, not primary muscle-cell destruction.

SCHEMATIC — CAUSAL RELATIONSHIP

Slide 61 · Lambert–Eaton: Characteristic clinical behavior

Patients typically present with extremity weakness.

Strength may improve after a few seconds of muscle activity.

Rapid repetitive nerve stimulation increases the muscle response.

These features reflect a presynaptic transmission defect.

Slide 62 · LEMS contrasts with myasthenia gravis

Feature

Lambert–Eaton syndrome

Myasthenia gravis

Primary autoimmune target

Presynaptic calcium channel

Postsynaptic ACh receptor or MuSK

Brief repeated activity

May augment strength

Weakness commonly worsens with exertion

Repetitive stimulation

Incremental muscle response

Decremental muscle response

Slide 63 · LEMS can be paraneoplastic or non-neoplastic

Chapter 27 states that about half of LEMS cases have underlying malignancy.

The most often associated malignancy is small cell lung carcinoma.

Symptoms may precede cancer diagnosis, sometimes by years.

Cancer-free cases often have other autoimmune disorders.

Slide 64 · Proposed tumor trigger in paraneoplastic LEMS

Small cell lung tumor expresses calcium channel

Host forms anti-channel antibodies

Antibodies react at motor nerve terminal

Presynaptic ACh release declines

Chapter 27 proposes shared channel expression as the immunizing stimulus.

SCHEMATIC — CAUSAL RELATIONSHIP

Slide 65 · Vignette: Weakness improved by exertion

TEACHING VIGNETTE

An adult has progressive proximal limb weakness.

Muscle response increases after brief repetitive stimulation.

Serology detects antibodies to a presynaptic calcium channel.

Identify the syndrome and the associated malignancy emphasized.

Slide 66 · LEMS vignette: Solve by physiology

Observation

Interpretation

Increment after repetitive stimulation

Suggests a presynaptic NMJ defect

Antibody to presynaptic calcium channel

Supports Lambert–Eaton syndrome

Relevant malignancy

Small cell carcinoma of lung

Caveat

LEMS is not necessarily associated with cancer

Slide 67 · CNS, sensory ganglion and NMJ are distinct lesions

Cerebellum

Limbic / ganglion

Neuromuscular junction

Purkinje-cell destruction

Neuronal loss + inflammation

Presynaptic channel blockade

Gliosis and chronic infiltrates

Cuffs, microglial nodules or ganglionitis

Impaired acetylcholine release

Coordination deficits

Cognitive / sensory disturbances

Weakness with facilitation

Slide 68 · Associate the marker with its anatomical target

PCA-1

Cerebellar Purkinje cells

Neuronal nuclear / anti-Hu

Neuronal nuclei; CNS/PNS

NMDA receptor

Hippocampal neuronal receptor

VGKC-complex

Limbic syndrome ± neuropathy

VGCC

Presynaptic neuromuscular junction

Associations are examples from the supplied Robbins chapters, not a complete antibody panel.

Slide 69 · Pattern recognition: Immune versus direct tumor effect

CONCEPTUAL DIAGNOSTIC REASONING

New neurologic syndrome in a patient with cancer?

Assess localization and tempo

Consider mass, infiltration or treatment effects

Look for syndrome-specific morphology and immune markers

Investigate occult tumor when syndrome antedates cancer

Conceptual clinicopathologic framework; Not a formal diagnostic guideline.

Slide 70 · Two linked treatment strategies

Recognize neurologic immune syndrome

Identify and manage associated neoplasm

Consider immunotherapy for selected immune syndromes

Assess neurologic improvement

Improvement in some patients following tumor removal and/or immunotherapy.

The text does not provide a universal management algorithm.

SCHEMATIC — CAUSAL RELATIONSHIP

Slide 71 · Immunotherapy targets circulating or cellular immunity

Removal of circulating antibodies among potential approaches.

Immunosuppression is another immune-directed strategy.

Clinical improvement is reported in some, not all, paraneoplastic syndromes.

The target antigen and mechanism influence how reversible the phenotype may be.

Slide 72 · Surface-directed antibodies tend to respond better

Plasma-membrane antigen examples

Intracellular-antigen syndromes

NMDA receptor and VGKC-complex are Robbins examples.

A neuronal nuclear or cytoplasmic target is intracellular.

Response to immunotherapy is generally better.

Immune therapy is less consistently effective.

Response is not guaranteed for an individual patient.

Neuronal destruction may already be established.

Slide 73 · Tumor control is a second therapeutic target

Removing the underlying tumor can diminish the antigenic stimulus.

Neurologic improvement in some patients following tumor removal.

Not all tissue injuries are necessarily reversible after the immune stimulus is treated.

Separately assess oncologic control and neurologic recovery.

Slide 74 · Syndrome-to-tumor quick reference

Syndrome

Classical association in the source

PCA-1–associated cerebellar degeneration

Ovarian / uterine / breast carcinoma

Neuronal nuclear antibody encephalitis

Small cell lung carcinoma

Anti-NMDA receptor encephalitis

Ovarian teratoma; Also sporadic cases

Childhood opsoclonus

Neuroblastoma

Paraneoplastic sensory neuronopathy

Small cell lung carcinoma

Paraneoplastic LEMS

Small cell lung carcinoma

Slide 75 · Integrated vignette: Distinguish three lesions

TEACHING VIGNETTE

Patient A: Purkinje-cell loss and cerebellar gliosis.

Patient B: Medial temporal cuffs and microglial nodules.

Patient C: Incremental response to repetitive stimulation.

Assign each patient to the correct tissue compartment and syndrome.

Slide 76 · Integrated vignette: Localization determines diagnosis

Patient

Key lesion or physiology

Most likely syndrome

A

Destruction of cerebellar Purkinje cells

Subacute cerebellar degeneration

B

Temporal encephalitic inflammation

Limbic encephalitis

C

Presynaptic transmission facilitates with activity

Lambert–Eaton myasthenic syndrome

Slide 77 · Consolidated clinicopathologic conclusions

A distant tumor can provoke immune-mediated disease in CNS, ganglia or neuromuscular junction.

Cerebellar degeneration and limbic encephalitis have distinctive tissue correlates.

Autoantibodies provide associations, but immune effector mechanisms differ.

A neurologic syndrome can appear before the cancer becomes clinically evident.

Tumor treatment and selected immunotherapy may improve outcomes.

Slide 78 · Primary source and scope

Robbins, Cotran & Kumar. Pathologic Basis of Disease. 11th ed. (2026).

Chapter 28: The Central Nervous System — Paraneoplastic Syndromes, pp. 1184–1185.

Supporting passages: Chapter 27 — Neuropathies Associated With Malignancy; Lambert–Eaton Myasthenic Syndrome.

Supporting context: Chapter 7 — Neuromyopathic Paraneoplastic Syndromes.

Morphologic diagrams are original editable schematics; no generated image is represented as a clinical specimen.